Merle Zimmermann found the following inspirational preface in a book on self-taught shorthand; the sentiments apply universally:

TO THE STUDENT

Reliable as this method is, let no one depend too much on either method or teacher. The work, remember, must be done by yourself; and the fullness of success can come to you in one way only—and that is by bringing to the work enthusiasm, energy, perseverance, and invincible determination; by being exacting with yourself, and never calling anything "good enough" that is not the best you can do; by putting an object at the end of every hour's practice, and never dawdling over the work simply to kill time; by adopting your motto "There is no such word as fail," and never losing sight of it.

Such common-sense measures, directed by a common-sense method, make failure not only improbable but absolutely impossible.